1. Field of the Invention
The invention relates to a thin film circuit board device for a keyboard, more particularly to a thin film circuit board device including first and second thin film circuit boards with protrusions folded together to interconnect electrically the first and second thin film circuit boards.
2. Description of the Related Art
Referring to FIG. 1, a conventional thin film circuit board device 8 is to be installed in a keyboard (not shown) and is shown to include a first thin film circuit board 81, a second thin film circuit board 82, and an insulator film 83 sandwiched between the first and second thin film circuit boards 81, 82. The first and second thin film boards 81, 82 include first and second conductive contacts 811, 821, respectively. The insulator film 83 has openings 831. For transmitting signals, the first and second conductive contacts 811, 821 are electrically connected to each other through a conductive paste (not shown) located in the openings 831 to bond adhesively the first and second conductive contacts 811, 821.
The conventional thin film circuit board device 8 is disadvantageous in that the conductive paste is likely to deteriorate after a period of time, which results in poor adhesion to bond the first and second conductive contacts 811, 821, which, in turn, results in disconnection between the first and second conductive contacts 811, 821.